1. Field of the Invention
The present invention relates to an ultrasonic device for sensing a touch-position.
2. Description of the Prior Art
A pointing device used for assisting the role of a keyboard is available as a means of producing an image or moving the image on a display panel. One of conventional pointing devices is, for example, the device named mouse. When producing or moving an image on a display panel by using the mouse, it is necessary to move the mouse itself on a plane, such as a rubber board, with some extent. Thus, an image based on evaluation with respect to a moving direction and a moving distance of the mouse on the plane is made on the display panel. However, since a point on the plane is not always placed on the corresponding point on the display panel, much of the work the mouse does is wasted. In addition, because of difficulty in controlling the mouse minutely, it often takes much time to produce an image on the display panel.
Thus, conventional pointing devices considerably waste time and energy on producing or moving an image on the display panel, moreover, have the difficulty on realizing a small-sized and simple structure.